m. S063. XORTH AMERICAN PARASITIC C0PEP0D8— WILSON. 



681 



Host and record of specimens. — The following list gives the hosts, 

 localities, specimens, and numbers of the large collection of this 

 species in the National Museum : 



Lot No. 7990 was remarkable for the fact that nearly every female 

 had at least one attached male and a few had as many as three or 

 four, usually fastened to the sexual process, sometimes to the neck, 

 and in one instance to the egg string. The specimens in the two lots 

 from the Pacific cod are similar in all respects to those fi-om the 

 Atlantic, but average larger in size. 



Specific characters of female. — Cephalothorax cylindrical, the same 

 diameter throughout, and a little longer than the trunk; head not 

 enlarged nor narrowed, but squarely truncated anteriorly; no dorsal 

 carapace; cephalothorax in line with the second maxillae and both 

 attached to the extreme anterior end of the trunk; the latter more 

 or less quadrilateral, with rounded comers, flattened dorso-ventrally 

 and somewhat reentrant at the center posteriorly; genital process on 

 a level with the ventral surface and minute; egg strings cylindrical 

 shghtly tapering posteriorly, and varying from one to two and a half 

 times the length of the trunk; eggs arranged in 10 or 12 longitudinal 

 rows, from 15 to 35 in a row. 



First antennae indistinctly three-jointed, tipped with two short 

 setae, and close to the base of the mouth tube; second antennae uni- 

 ramose, the basal joints lying along the sides of the head and sup- 

 ported by strong chitin ribs, the terminal joints bent squarely across 



